More than 70 years in the making, the long-awaited sequel to the notorious 1936 film, Reefer Madness has arrived. It's called The Purple Brain, and just like its unintentionally campy predecessor, its purpose is to frighten Americans about marijuana.

The particular target audience for the Feds' new production is the millions of parents who may have, without incident, experimented with marijuana in the 1970s, when they were about the same age as their children are today.

The plot is as follows: Sure, the pot you and your 40-something peers once enjoyed may have been innocuous, but that's only because it bears no resemblance to the super-potent weed of today-- strains with such foreboding names as "Train wreck," "AK-47," and "The Purple." As proclaimed by Drug Czar John Walters recently, "[W]e are no longer talking about the drug of the 1960s and 1970s -- this is [in computer parlance] Pot 2.0."

To top off this frightening message, unsubstantiated claims of "brain damage" resulting from the use of this super-pot are new buzzwords in today's Prevention circles.

If ever there was an attention-getting script for scaring the hell out of parents, this is it.

Fortunately, while the headlines are grabbing, the story lacks credibility.

Growers in the business of selling marijuana have always attached pet names to selected strains of pot. In the 1970s, popular varieties included "Acapulco Gold" and "Maui Wowie." Today, as in the past, most of these labels are little more than clever marketing gimmicks devised by producers and sellers to distinguish their particular product in a highly competitive marketplace.

While a handful of potent strains may be available in limited quantities today, these varieties compose only a minute percentage of the overall marketplace -- at a price tag that is cost-prohibitive to anyone but the most wealthy of aficionados. For others, marijuana remains essentially the same plant it has always been, with its relatively mild rise in average potency akin to the difference between beer and wine.

Unlike alcohol -- or even aspirin, -- today's marijuana still poses no risk of fatal overdose, regardless of the strength of its primary psychoactive ingredient, THC. Moreover, cannabis consumers readily distinguish between low and high potency marijuana and moderate their use accordingly.

Finally, despite claims that marijuana alters the brain, it is important to note that THC -- regardless of its potency -- is surprisingly non-toxic to the adult as well as the teenage brain. Recently scientists at the Nathan S. Kline Institute for Psychiatric Research reported that they could find "no ... evidence of cerebral atrophy or loss of white matter integrity" attributable to cannabis use in the brains of frequent adolescent marijuana users (compared to non-using controls) after performing MRI scans and other advanced imaging technology. Separate studies assessing the cognitive skills of long-term marijuana smokers have also reported no demonstrable deficits.

Of course, marijuana is an intoxicant that should be avoided until and unless an individual has reached an age of mental and physical maturity, and this might be well into his or her twenties.

But as we urge adolescents to abstain or at least delay, let's not forget the lessons we've learned after two decades of drug education that has failed to convince students to "just say no." When teens ultimately learn the truth, exaggerated campaigns like "The Purple Brain" do little more than create skepticism about anything adults tell them about drugs, not to mention fueling their natural curiosity.

What's really frightening is that when teens realize they've been deceived about marijuana, they tend to disregard warnings about the very real dangers of hard drugs like cocaine and heroin. It's this latter scenario that ultimately trumps The Purple Brain as the real horror show.